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At least 73 records · Page 4Linked to original sources
PubMed2006

Antibacterial activity of coffee extracts and selected coffee chemical compounds against enterobacteria.

The in vitro antimicrobial activity of commercial coffee extracts and chemical compounds was investigated on nine strains of enterobacteria. The antimicrobial activity investigated by the disc diffusion method was observed in both the extracts and tested chemical compounds. Even though pH, color, and the contents of trigonelline, caffeine, and chlorogenic acids differed significantly among the coffee extracts, no significant differences were observed in their antimicrobial activity. Caffeic acid and trigonelline showed similar inhibitory effect against the growth of the microorganisms. Caffeine, chlorogenic acid, and protocatechuic acid showed particularly strong effect against Serratia marcescens and Enterobacter cloacae. The IC(50) and IC(90) for the compounds determined by the microtiter plate method indicated that trigonelline, caffeine, and protocatechuic acids are potential natural antimicrobial agents against Salmonella enterica. The concentrations of caffeine found in coffee extracts are enough to warrant 50% of the antimicrobial effect against S. enterica, which is relevant to human safety.

Alkaloids↗
PubMed2003

Estimation of production losses caused by the coffee berry borer (Coleoptera: Scolytidae) and calculation of an economic damage threshold in Togolese coffee plots.

The coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae), which exists in all coffee producing zones, is a major pest. The seriousness of this scolytid was assessed in Togolese plots spread over five agroclimatic zones, by determining the attack rate from a sample of coffee trees. The work was carried out over 2 yr and revealed that weight losses were proportional to the attack rates. The average infestation rates were 5.64% in the first year and 6.36% in the second year, while total production losses amounted to 2.60% and 3.18%, respectively, for the same periods. Generally speaking, attack rates in the plots were low and varied considerably within a given zone. Plantations located on plateau were more severely attacked than those in the plains. A relationship was established between total losses and the cost of insecticide treatment; this relationship was used to calculate an economic damage threshold beyond which control proves to be cost effective.

Animals↗
PubMed2006

Do you like the sight or the feel of milk in coffee? Ecology and effortful attention in differential acuity and preference for sensed effects of milk substitute in vended coffee.

A rapid method of discrimination scaling was used to measure individuals' acuity for levels of a complex stimulus perceived through several sensory modalities at once in a familiar context. The stimulus was a replacement for fresh milk used in vended coffee. The two experiments reported here compared the performance of ratings of the coffee's milkiness and creaminess when assessors were limited to the use of visual and/or olfactory cues. Better discrimination by milkiness ratings was observed during normal drinking and in a visual-only condition than when only oronasal or oral cues were available. Ratings relative to each assessor's ideal level of milkiness or creaminess showed diversity between assessor-preferred visual and oral characteristics of the milk substitute. However, instructing the assessor to attend to a particular aspect of the sample did not prevent the use of a better-discriminated characteristic if available to the senses. These results showed that the acceptability of a beverage or food depends more on the perceptible material than on efforts to direct attention to particular aspects.

Adult↗
PubMed1997

Trigonelline, a naturally occurring constituent of green coffee beans behind the mutagenic activity of roasted coffee?

Trigonelline and amino acids are natural components in green coffee beans. Model systems mimicking coffee roasting were used to produce heated samples of trigonelline, amino acids and glucose. Trigonelline and amino acids were heated separately or in combinations for 20 min at 250 degrees C. The results of bacteria mutation assays (Salmonella typhimurium strains TA 98, YG 1024 and YG 1029) showed that trigonelline, alone or in combination with most of the single amino acids and mixtures of amino acids, yielded potent mutagenic activity. Of the singly heated compounds, the highest mutagenic activity was found for trigonelline. The mutagenic activity detected with metabolic activation of the heated trigonelline samples indicated that the mutagenic compounds might be amines; however, higher mutagenic activity was found for trigonelline and its combinations without metabolic activation, which suggests that other types of mutagens (direct-acting) were predominant. High-performance liquid chromatographic analysis of some of the heated samples did not reveal the presence of any known mutagenic heterocyclic amine.

Alkaloids↗
PubMed2002

Headspace sorptive extraction (HSSE), stir bar sorptive extraction (SBSE), and solid phase microextraction (SPME) applied to the analysis of roasted Arabica coffee and coffee brew.

Headspace sorptive extraction (HSSE) and stir bar sorptive extraction (SBSE), two recently introduced solventless enrichment techniques, have been applied to the analysis of the headspace of Arabica roasted coffee and of the headspace of the brew and of the brew itself. In both HSSE and SBSE enrichment is performed on a thick film of poly(dimethylsiloxane) (PDMS) coated onto a magnet incorporated in a glass jacket. Sampling is done by placing the PDMS stir bar in the headspace (gas phase extraction or HSSE) or by immersing it in the liquid (liquid phase extraction or SBSE). The stir bar is then thermally desorbed on-line with capillary GC-MS. The performance of HSSE and SBSE have been compared through the determination of the recoveries and relative abundances of 16 components of the coffee volatile fraction to classical static headspace (S-HS) and to headspace and in-sample solid phase microextraction (HS-SPME and IS-SPME, respectively) applying the fibers PDMS 100 microm, Carbowax/divinylbenzene 65 microm (CW/DVB), Carboxen/PDMS 75 microm(CAR/PDMS), polyacrylate 85 microm(PA), PDMS/divinylbenzene 65 microm(PDMS/DVB), and Carboxen/divinylbenzene/PDMS 50-30 microm(CAR/PDMS/DVB). In all cases, HSSE and SBSE gave higher recoveries, and this is entirely due to the high amount of PDMS applied.

Chromatography, Gas↗
PubMedDate not supplied

Effects of simultaneous treatment with hydroxyapatite and coffee cherry, the residue left after the removal of coffee beans, on spontaneous mammary tumourigenesis and related parameters in SHN mice.

We have found that the chronic administration of the diet containing 5% hydroxyapatite (HAP) derived from bovine or swine bone or drinking water containing 0.5% extract of coffee cherry (CC), the residue left after the removal of coffee beans, induced a marked inhibition of spontaneous mammary tumourigenesis in SHN mice, while the effects decreased with age. In the present study, the combined effects of HAP and CC on mammary tumourigenesis and related parameters were examined. The inhibitory effects of HAP or CC alone on the development and/or the growth of mammary tumours were reduced by HAP + CC. Decreased food and water intake and retarded body growth caused by CC were ameliorated by HAP. Enhancement by HAP or CC of the excretion of the urine components was mostly nullified by HAP + CC. Parameters such as normal mammary gland growth and uterine adenomyosis on which neither HAP nor CC had an effect also did not respond to HAP + CC. These findings suggest that the target is important when administering natural products in combination if the agents are to manifest their effects, additive, synergistic, antagonistic or otherwise.

Animals↗
PubMed2001

Effects of coffee cherry, the residue left after removal of the beans from the coffee fruit, on mammary glands, automatic behavior and related parameters in mice.

To clarify the mechanisms of the anti-mammary tumor activity of coffee cherry (CC), the residue left after the removal of beans from the fruit, the effects in SHN mice of CC on plasma and urine component levels, mammary gland growth, spontaneous motor activity and several related parameters were examined. Hot water extract of CC was given to 2-month-old mice in drinking water (0.5%) for 60 days. The treatment prevented the elevation of plasma and urine levels of alanin amino-transferase and asparate aminotransferase, indicating that CC can protect against metabolic abnormality, which is a cause of the high mammary tumor susceptibility of SHN mice. It also resulted in an inhibition of the formation of precancerous mammary hyperplastic alveolar nodules. Neither food and water intake nor spontaneous motor activity was affected by CC. The findings provide novel information on the mechanism of the protective effect of CC on mammary tumorigenesis and confirm the usefulness of CC as a safe chemopreventive agent of mammary and other types of tumors.

Alanine Transaminase↗